Angiosarcoma of the breast - specific findings of MRI.

We present a case of low-grade angiosarcoma of the breast. A 26-year old woman presented with a lump in the left breast. An elastic hard and ill-defined tumor, 80 x 50 mm in size, was palpated in the upper region of her left breast. Mammography showed a dense lesion with poorly defined border. Ultrasonography showed a hyper-and hypo-echoic lesion with an unclear border, but no definite tumor. Fine needle aspiration cytology showed no evidence of malignancy. Therefore, she was followed with a diagnosis of mastopathy. Six months later, the lump got enlarged. A contrast-enhanced MRI of the breast was performed. It showed a 100 x 60 mm enhancing vascular mass. Most parts of the tumor enhanced remarkably at the early phase, and prolonged enhancement was recognized at the late phase. Core needle biopsy was performed, and a possible angiosarcoma was diagnosed. It is not easy to diagnose the mammary angiosarcoma. MRI may contribute to the accurate diagnosis and play an important role regarding this entity.